Abstract
The entire life of the plant cell is intimately related to the biogenesis of cell wall and growing attention has been devoted in last years to the understanding of the biochemical events that lead to the synthesis and cross-linking of the major wall components. In this context it is now clearly assessed that proteins play a key role in the architecture and chemo-rheological properties of growing cell wall thus participating in important ontogenetics events such as growth and differentiation. Wall proteins are mostly glycoprotein accounting up to almost 20% wall dry weight and many of them are structural proteins. Here we are dealing with enzymatic proteins occurring in the cell wall and their physiological significance.